Stepping switch



June 17, 1952 E. F. THIERFELDER 2,500,933

STEPPING SWITCH Filed Sept. 20, 1949 5 Sheets-Sheet l INVENTOR E. F.' THIERFELDER ATTORNEY June 17, 1952 E. F. THIERFELDER STEPPING SWITCH Filed Sept. 20, 1949 5 Sheets-Sheet 2 m w w m m m m.

INVENTOR E.E THIERFELDER ATTORNEY FIG. 4

June 1952 E. F. THIERFELDER 2,600,938

STEPPING SWITCH Filed Sept. 20. 1949 5 Sheets-Sheet a FIG. 3

INVENTOR EE THIERF'ELDER ATTORNEY J ne 7, 1952 E. F. THIERFELDER 2,600,938

STEPPING SWITCH Filed Sept. 20, 1949 5 Sheets-Sheet 4 la i "17 37 111M221: u l8 \nfifise 4a 65 63 FIG] I? 23 24 34 Wm m/ m m m m INVENTOR E F. THIERFEL DER ATTORNEY J1me 1952 E. F. THIERFELDER 2,600,938

STEPPING SWITCH Filed Sept. 20, 1949 5 Sheets-Sheet 5 Q 2' LL.

n I. g l N n J h m INVENTOR o E. E THIERFELDER 0 0 0 I I +2 BY Ml 36 ATTORNEY Patented June 17, 1952 STEPPING SWITCH Emil F.'Thierfelder, Springdale, Conn., assignor to Remington "Rand 1110., New York, N."Y., a corporation ofDelaware Application September 20, 19 19; Serial 'No'. 116,7 65

3-Glaims. l

- This invention relates to improvements instepping switches and in particular to one: in which series of contacts and contact plates can be connected in circuit alternately and successively.

Theconventional stepping switch, as developed for automatic switching in the telephcne art, is arranged in decks with each deck having apluralityof contacts arranged about an .arc concentrio with a shaft carrying double endedsW-itch arms for each deck. Contactis made with the insulated switch arm by means of a brush one for each deck, extending from. the arc-Iof contacts to make sliding contact with theenlarged center portion of each switch arm. .such a construction limits to one the number ofcircuits thatcan be completed through the. branches represented by the contacts of one level.

"The present invention removesithis: limitation by eliminatingthe brushes and utilizing'the. previously unused second. end of 1th6=SWltCh arm tomake contact with a seriesofarcuate plates representing the several circuits tobe'successively connected to the branchesrepresented -by.r-the contacts. One double ended switch-arm .is: used for. :each arcuateiplate .for each circuit towbe.

switched on each level, so that .each level-can control as many circuits ascan .beco-nveniently fitted into the space available.

For instance, in a calculator utilizingjthevpartial .products andmultiplicationtable. principle formultiplication it is desirable to'have a multiplication table for each order of the factor having. the greatest number :of digits. i. e.. 61in a 6 x 6.multiplier.: Each'multiplier must; be capable of. indicating both the units .andtensdigits of the various possible partialproducts. Stepping switches 'ofithe conventional type have been used .for this purpose. The contactpositions have been used-to representthe digits oixthe multiplier and the decks to representlthe digits, of the. multiplicand. The contact atthe selected position, inthe selected \deck then represents either the unit or the tens digit of the partial product, thus requiring two ofythe conventional stepping switches to represent a single partial product.

-With a stepping switch constructed according to thepresent invention, a'single switch represents both the units and-tens of the partial. product of each order of the factors,.thus halving the number of switches needed andreducingthe bulk, weight and cost of the multiplier byproviding two switch arms and two arcuate contact plates on each level.

aThe principal objectci the present invention.

:2 therefore, is to -provide animproved stepping sw-i-tchadapted to; select circuits from vrseveral groups :of circuits =at-each level.

A more specific object is to -provide a novel stepping switch having more-decks of contacts within the same lateral space.

Another object is to provide anovel: improved stepping switchadapted to perform the functions-of several conventional stepping switches within the space occupied by one switch of the conventional type.

I Another-object of the invention isto provide a novel improved stepping switch adapted to control circuits in the performance of theseveral functions-of a-calculatonsuch as addition,

subtraction, and multiplication.

Another objectis to-provide anovel improved steppingswitch for use as a multiplication table in a calculator in which. a single switch can-be used for-determining both the tens and units of the partial products. of one order of the desired factors simultaneously.

Other :objectsand structural detailswill be apparent from the followingdescription .when

, read in connection with the accompanyingdrawings wherein:

oppositefrom thatillustrated in Fig. 2;

Fig; 7- is a bottom plan view with referenceto Fig. 6; and

-F-ig.--8 is schematic representation 'of acircuit in-which for example, the switchmay be used.

Referring to the-drawings in detail, andin particular to Figs. 1 and 4-there. is provided a frame l El formed with a semi-circular portion l I upon which are supported twenty-six strip conv,tacts .12 which are, made of copper or other c onductive material and are arranged in'eleven arcs separated from each other by arcuate insulators I3. andheldin place by an arcuate plate l4 that binds the contact. assembly togetherthrough bolts l5 andnuts I6.

Attached to the frame I is a bracket l1 adapted to support sets of arcuate commutator contact plates 18 made of copper or other conductive material arranged in eleven decks, one pair to a deck and each pair separated from the other by arcuate insulators 20. The whole is bound together between arcuate plates 2! and attached to the bracket I! by means of bolts 22 and nuts 23 and separated from the bracket I! by spacers 24 so that each deck of commutator contacts I8 is coplanar with a deck of contacts I 2.

A bracket 25 is attached to the frame ID by screws 26. Ears 21 are formed integral with the bracket 25 on opposite sides thereof for support ing the wiper assembly 28 (Fig. 2) journalled. in said ears, mounted on an axle 29 and upon which is fixed a ratchet wheel 30 and eleven double armed wipers 3| mounted in pairs at right angles to each other and separated from each other by insulator discs 32. Each wiper 3i is arranged to have one of its tips 33 sweep across a deck of contacts [2 while the other tip sweeps two commutator segments [8 one after the other, so that a conductive path is successively provided between each commutator segment and the thirteen contacts diagonally opposite it. As seen in Fig. 4, the near wiper in clockwise movement will sweep the first quadrant of contacts with its upwardly extending arm while the depending arm will sweep the contact plate 18 in the third quadrant. During the same action, the adjacent wiper will sweep the contacts and the plate of the second and fourth quadrants respectively.

Arm portions 34 integral with the bracket 25 support a heavy rod 36 and a light rod 31 (Fig. 7). On these rods are mounted a U-shaped coil yoke 38, an armature 40 and an armature backstop 4|. The coil yoke 38 supports a core 42 on its central portion. The core supports a magnet coil 43. The U-shaped armature 40 is supported, with its central portion in front of the outer end of the core 42, on its arms 44 that are pivotably mounted on the light rod 31.

The side arm 44 of the armature 40 that is on the same side of the switch as the rachet 30 has a lever 45 pivotably mounted at its inner end. The long end of this lever ends in a pawl 46 that is adapted to engage the teeth 41 of the racket wheel 30. The lever 45 is urged clockwise as seen in Fig. 2 by a spring 48 attached to its short end at 50 and to a lug formed integral with the side arm 44 of the armature 4U.

Mounted on one side of the outer portion 52 of the coil yoke 38 (Figs. 2 and 4) is a contact and spring pileup unit 53 comprising four U-shaped plates of resilient metal, one plate 54 carrying a contact 55 on the outer side of one of its arms and having facilities for making electrical connections on its other arm. The adjacent or next lower piece 56 carries two contacts 51 and 58 on either side of the arm immediately over the piece 54. This arm extends beyond the lower piece 54 and is adapted to exert pressure on a lug 60, formed in the lower edge of the side arm 44 of the armature 40, and having a cap 6| of insulating material. The next lower piece 62 bears a contact on the under side of the arm directly over the last mentioned piece 56. The outermost piece 63 is the largest of all and is arranged to exert spring pressure on the side arm 44 of the armature 4D fitted with a lever 45 through a cap 64 of insulating material fitted on the lug 5|. The plates 54, 56, 62 and 63 on the spring pile up unit 53 are separated by insulators 65 and fastened together and to the coil yoke 38 by screws 66.

A screw 61 mounted in a slot 68 on the ear 2'! of the racket side of the bracket 25 maintains the pawl 46 in proper position to engage the teeth 41 of the racket wheel 30. A plate 10 of spring material is formed with a pawl H at one end and is attached to the under side of the bracket 25 by screws 12 to prevent the racket 30 from slipping when the pawl 46 is not engaged.

When the relay coil 43 is energized it attracts the armature 40 to its core 42 lowering the arm 44 which carries with it the lever 45 against the pressure of the spring leaf 63 so that the pawl 46 is disengaged from the teeth 4'! of the rachet 30. The spring 48 urges the pawl 46 into engagement with a lower tooth 41 on the racket 30. When the coil 43 is deenergized the spring leaf 63 urges the arm 44 upwardly carrying with it the lever 45 still having its pawl 46 in engagement with a tooth 41 of the racket wheel 30 to move the latter one tooth space clockwise as seen in Fig. 2. The space between the teeth equals the space between the contacts I2. The rachet wheel 30 carries with it the switch arms 3: so that their tips 33 travel onto the next contact on each quadrant of each level of contacts to break one current path and set up another.

The invention has been shown embodied in a modified stepping switch of the spring operated type. The invention could also be embodied in stepping switches of the magnet driven type having a release magnet to permit reversal and return to the starting position by the use of a different driving structure and the modification of the shape of the wiper tips to permit operation in both directions.

lhe above described switch may be used as an adding device by connecting the contacts l2 and the commutators 18 by wires in the manner shown schematically in Fig. 8. In this view three decks and three pairs of arms have been shown in an exploded perspective View without the supporting or driving structures to bring out the electrical connections. Only a few contacts [2 on each deck have been shown by way of illustration. It is to be understood that in most applications there would be more decks and more contacts on each deck.

It will be seen that the decks have been indicated by the letters A, B and C. The commutator contacts l8 have been designated T or U representing units or tens digits of partial products. The commutator for the units digits of the first deck is designated UA and that for the tens digits of the second deck TB etc. These commutator contacts are each connected by a wire "I0 through a normally open switch contact H to a source of electrical energy such as a battery 12. The other side of this battery is connected to ground. Each contact I8 is designated by the digit it represents 1, 2 etc., either T or U depending upon whether it represents a digit of the units or tens and a letter A, B or C depending upon what deck it is in. The first contact in the tens group of the C deck is thus represented by lTC. It will be seen that contact 3UA is connected to contacts ZUB and IUC. Similarly other contacts are connected to the contact of the equivalent group in the next deck representing the next lowest number. The group of contacts not so connected is then connected to a solenoid arranged to print the highest number represented by the contacts so connected. The effect is to provide an adding device. The first position in deck C will print a 3 as will the second position in deck B and the third position in deck A. As each sucessive deck is energized by the closing of the switch between its commutator contact and the battery a given position will represent successively higher values. The first amount to be added determines the position of the switch arms and the second amount determines which switch arm is energized and so which numeral printing solenoid is energized to print the total.

The switch may also be connected up for use as a multiplication table and partial products type of multiplier. In such an arrangement one section represents the units digits of the partial product and the other section represents the tens digits. the position of the switch arms. Each deck represents a possible multiplier. As an example, in multiplying six times six, the multiplicand is represented by positioning the switch arms to the sixth position. The multiplier is represented by completing the circuit to the sixth deck. This completes a circuit to the sixth contact on the sixth deck of each section. The units digit of which is 6 and the tens digit 3. Thus, to print the product, the sixth contact of the sixth deck of the units section must be connected to the 6 units solenoid; and the sixth contact of the sixth deck of the tens section must be connected to the 3 tens solenoid.

Similarly for four times four the fourth contact of the fourth deck of the units section must be connected to the 6 solenoid and the fourth contact of the fourth deck of the tens section must be connected to the 1 solenoid. Those contacts in the units section, representing partial products having the same digit in the units order, are connected together and to the solenoid representing that digit and this also applies for the tens section. A connection of this sort is not shown but can be easily worked out in any convenient manner.

The circuit by which the switch arms are positioned may be any of several well known design and as these arrangements are not a part of the present invention, it is not believed necessary to show such a circuit.

While I have described what I consider to be highly desirable embodiments of my invention, it is obvious that many changes in form could be made without departing from the spirit of my invention, and I, therefore, do not limit myself to the exact form herein shown and described, nor to anything less that the whole of my invention as hereinbefore set forth, and as hereinafter claimed.

What I claim is:

1. In an electrical circuit stepping switch, a plurality of tiers of insulated contacts, each tier including radially extending contact strips arranged in spaced relation with each other in arcs constituting quadrants of a circle, contact plates of quadrant shape disposed in spaced relation to each other and to the strips and com- The multiplicand is represented by pleting a circle with said strips, the strips and the plates of each tier being substantially coplanar, a shaft, a pair of wipers for each tier mounted on said shaft and each pair of wipers presenting arcuately spaced tip ends for simultaneous sweeping engagement with the contact strips and the contact plates, and means for rotating said shaft to impart a sweeping movement to said wipers to successively provide a conductive path between each contact plate and the contact strips of a quadrant.

2. In an electrical current stepping switch, a plurality of tiers of insulated contacts, each tier including radially extending contact strips arranged in spaced relation with each other about a semicircle, contact plates of quadrant shape disposed in spaced relation to each other and to the strips and completing with said strips a circle, the strips and the plates of each tier being substantially coplanar, a shaft, a pair of wipers for each tier mounted on said shaft, the wipers of each pair being arranged at right angles to each other and each wiper of the pair presenting diametrically opposite tip ends for simultaneous sweeping engagement with the contact strips and the contact plates, and means for rotating said shaft to impart a sweeping movement to said wipers to successively provide a conductive path between each contact plate and the contact strips in a quadrant diametrically opposite said plate.

3. An electrical stepping switch as set forth in claim 1 in which said shaft rotating means includes a ratchet gear secured to the shaft, the teeth of the ratchet being spaced to coincide with the spacing of said contact strips and means for intermittently rotating the ratchet gear one tooth at a time.

EMIL F. THIERFELDER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 330,244 Lange Nov. 10, 1885 498,291 McCaskey May 30', 1893 974,955 Dyson Nov. 8, 1910 1,168,003 Horton Jan. 11, 1916 1,200,885 Schmid Oct. 10, 1916 1,324,401 Magrath Dec. 9, 1919 1,437,267 Perkins Nov. 28, 1922 1,472,465 Forsberg et al Oct. 30, 1923 1,533,188 I-Iargan Apr. 14, 1925 1,731,977 Harrison et al Oct. 15, 1929 1,954,092 Muller Apr. 10, 1934 2,025,534 Sheard et al Dec. 24, 1935 FOREIGN PATENTS Number Country Date 133,056 Austria Apr. 25, 1933 343,983 Great Britain Feb. 27, 1931 

